Prediction of lymphatic invasion by peritumoral lymphatic vessel density in prostate biopsy cores

Abstract

Lymphatic invasion in radical prostatectomy specimens has been suggested to be an unfavorable prognostic factor in clinically localized prostate cancer. Lymphangiogenesis detected by antibodies specific for lymphatic endothelial cells has been associated with lymphatic invasion and lymph node metastasis in prostate cancer. This study was designed to examine whether lymphangiogenesis in prostate biopsy could predict lymphatic spread in radical prostatectomy specimens. Paraffin-embedded positive biopsy cores obtained from 99 patients who underwent radical prostatectomy at our institution were immunostained with D2-40 monoclonal antibody, which specifically recognizes lymphatic endothelium. The association between lymphatic parameters in prostate biopsy and pathological parameters in radical prostatectomy specimens was analyzed. Peritumoral and intratumoral lymphatic (ITL) vessels were observed in 90 (90.9%) and 23 cases (23.2%). Average and maximal peritumoral lymphatic vessel density (PTLD) and the presence of ITL in positive biopsy cores were significantly associated with positive biopsy core rates (P = 0.0015 for average PTLD, P < 0.0001 for maximal PTLD, and P = 0.0038 for ITL) and lymphatic vessel invasion (P < 0.0001 for average PTLD, P < 0.0001 for maximal PTLD, and P = 0.0322 for ITL). Among preoperative parameters, the biopsy Gleason score (P = 0.0092, HR = 6.108) and average PTLD (P = 0.0034, HR = 1.860) were significant predictors of lymphatic invasion in radical prostatectomy specimens in multivariate analysis. PTLD in prostate biopsy specimens assessed by immunohistochemistry using D2-40 antibody could be a useful parameter for predicting lymphatic spread of clinically localized prostate cancer.